See Castle Street East 1 to 15 &c in London Addresses database
No 10 Castle St East Harris's List 1790 Miss H-w-rd
According to the text of Harris's List she was called Polly (usually short for Margaret) was aged about 19 and had been a servant at the Thirteen C-nt-ns. There were several inns or eating houses called the Thirteen Cantons in London at the time and it was a common name for Switzerland and many of the customers may have been Swiss. One was in King St Soho and another in Moor St Soho, probably the same one referred to as being in St Giles. Another was at 33 Charing Cross and another near Temple Bar, and one near Irongate (presumably Irongate Wharf, St Catherine's, Tower Hill). See Pignaud, Philip .